Astrophotography Help
I have set this page up to use as a file repository for questions and file posting that will allow me to get or provide help to
others hobbyists.   

You can reach me at or on CloudyNights forum as MadMan

                               Homemade laser collimation for SX cameras.  

Could be much improved on but this took 1 hour and I wanted to get it done before a dark sky trip.   Below are the 'ingredients' - and it works for now quite well.  This
proves that using a equi-gap method of collimating SX cameras is NOT a good place to start as the gaps between the body and the tip/tilt plate at the collimation screws vary
greatly when the camera is perfectly collimated.  The CCD is installed in SX cameras on double sided tape and thus varies in position enough to make this a worthwhile

Per the picture below, the objective is to get the bright spot highlighted with the yellow arrow not to rotate as you rotate the camera.  Make your own with.....

- a green laser pen with a finder type holder or just laid and taped to a block of wood and pointed right at the CCD face (shutter must be open if present)
- A couple of 75 mm finder rings (ADM makes a great set)
- A 2" nosepiece and 40 mm Baader or other extension
- A way to hold the rings securely to a board (I used a spare vixen dovetail and some clamps)
- A wall to project onto (or a piece of paper if you don't want to piss off your wife for drawing on the spare fridge I have in the garage)
- 2.5 and 2mm ball drivers (much easier to get at the screws than allens to make 'on the fly' adjustments)
- A pencil :)

Loosen the set screws.  Tighten the camera pretty well in the rings and rotate the camera while applying a little forward pressure in the direction that WON'T cause the
nose piece to unscrew :).  Adjust the tip/tilt plate silver collimation screws (after loosening the set screws) as you rotate the camera slowly to try and center the close dim
spot next to the brightest spot.  See marked image below.  Don't forget to re-tighten (just snug) your set screws when done.  No more star trails in the corner of your images
(unless something else is amiss).

                                                      HAPPY COLLIMATING!!!!!!!!!!!!
12/16/11 Update: Home made collimation setup further results -
After aligning using the brightest spot in my test images below such that it did not move while rotating the camera, I still had a uniform tilt to my CCD
Inspector results.  I suspected that if I lessened the angle between the laser and the CCD (made it more perpendicular), it might be better.  It did and I now
have a perfectly collimated camera.  I moved the pen such that it almost eliminated the angle while still allowing the beam to pass to the side of the pen and
onto a projection wall some 4 feet away.  Projecting onto a wall provides more accuracy than the roofing shingle did.  Good luck!
Original Angle - beam to
CCD surface -  
Collimation Results
Significantly Lessened
Angle Collimation
Results.  Could be just
luck and not the angle -
but I do think CCD
inspector works well
based on just looking at
how the image brightned
and tightened.
20 second image of
Messier 35.  Tak 106 fsq
at prime.  No changes to
focus or setup between
pictures.  Only one
image was taken with
each attempted
collimation (other than a
wrong exposure in
between) and the 2nd
results were achieved on
the first try (colltest3).  
To the right: the
original 'all wood'
testing platform.  
Extension instead
Files Section:
Jellyfish Nebula - Narrowband
SiiHaOiii rendition - 4 hours - 32
bit FIT file from PixInsight
Gerd Neuman CTU unit with Canon
Bayonet for CCD use
Astrotrac related
Flat Issue with SX Active Optics
unit at f10 and filter
The objective is to get the CCD surface spot to center when
the camera is spun.  Below is my current collimation rig with
my 60Da doing 4 second exposure while I spun the camera.  
Collimation is almost perfect (images right) I think or I would
see 3 circles in the center.
Misc Help Files
Sample H694 Ha FIT raw exposures
- 10m and 20m - Lagoon